Odeillo solar furnace, Solar furnace research facility in Font-Romeu-Odeillo-Via, France

The Odeillo solar furnace is a large research facility in the Pyrenees that uses mirror systems to concentrate sunlight onto a central point. The structure consists of several mirror sections working together to create extremely high temperatures.

In 1946 chemist Félix Trombe used an anti-aircraft mirror at Meudon to melt ore with concentrated sunlight, then built a first solar furnace at Mont-Louis in 1949. The Odeillo furnace, designed by architect Henri Vicariot, was built from 1962 to 1968 and commissioned in 1969.

The site's name comes from the village of Odeillo, part of Font-Romeu-Odeillo-Via in the Cerdagne. Since 1990 a visitor centre, Héliodyssée, explained solar energy and CNRS research until it closed in 2017; explanatory panels outside remain freely accessible. The furnace and the nearby Mont-Louis furnace have served as models for solar installations worldwide.

The Héliodyssée information centre closed in 2017, but explanatory panels outside remain free to read. The open-air facilities, including the heliostats on the slope and the parabolic concentrator, can still be viewed from outside. The site lies in Font-Romeu-Odeillo-Via, with the Mont-Louis solar furnace and the Thémis tower nearby.

The concentrated spot is about 1 metre across in the French account and 40 cm in the English one, yet it reaches up to 10,000 suns, or 10,000 kW/m². Operators vary the power by selecting which of the 63 heliostats to use and by opening the tower's protective doors.